#include "fbuffer.h"
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

void bufInit (buf *b)
{
	b->rw = NULL;
	b->rownum = 0;
}

/* Add a row to the file buffer */
void rowAddLast (buf *b, char *s, int len)
{
	/* Extend the block of memory containing the lines */
	row *newr = realloc(b->rw, (b->rownum + 1) * sizeof(row));
	//if (newr == NULL) termDie("realloc in rowAddLast");
	b->rw = newr;

	/* Allocate memory for the line and copy it
	 * at the current row number */
	b->rw[b->rownum].chars = malloc(len  + 1);
	//if (b->rw[b->rownum].chars == NULL) termDie("malloc in rowAddLast chars");
	memcpy(b->rw[b->rownum].chars, s, len);
	b->rw[b->rownum].chars[len] = '\0';
	b->rw[b->rownum].size = len;
	updateRender(&b->rw[b->rownum]);
	b->rownum++;
}

void rowAddChar (row *rw, char c, int pos)
{
	/* Check if char is valid */
	if (!c || (iscntrl(c) && c != '\t')) return;
	
	/* extend the string */
	rw->size++;
	char *t = realloc(rw->chars, rw->size + 1);
	//if (t == NULL) termDie("realloc in rowAddchar");
	rw->chars = t;

	/* make space for the new char */
	memcpy(&rw->chars[pos + 1], &rw->chars[pos], (rw->size + 1) - (pos + 1));

	/* add the new char */
	rw->chars[pos] = c;

	updateRender(rw);
}

int rowDeleteChar (row *rw, int select, int pos) // WIP
{
	/* Check if the character is valid */
	if (rw->chars[pos - 1] == '\0' && pos) return 0;
	if (!pos && !select) return 0;
	if (rw->chars[pos] == '\0' && select) return 0;
	//change pos based on the command
	if (!select) pos--;

	memcpy(&rw->chars[pos], &rw->chars[pos + 1], rw->size - pos);

	char *s = realloc(rw->chars, rw->size);
	if (s != NULL) rw->chars = s;
	rw->size--;

	updateRender(rw);
	return 1;
}

void rowAddRow (buf *b, int pos, int cur) // WIP; TO DOCUMENT
{
	/* 	MOVE THE ROWS AWAY */
	/* add another line to the bottom containing the previous
	 * (last) line, effectively making new space */
	rowAddLast(b, b->rw[b->rownum - 1].chars, b->rw[b->rownum - 1].size);

	/* copy all other lines until the specified position to the next one */
	for (int last = b->rownum - 1; last > pos; last--)
		rowCpy(&b->rw[last], &b->rw[last - 1]);

	/* SPLIT THE ROW AT POS AND STORE IT */
	/* Get the row length at position after the cursor */
	int len = b->rw[pos].size - cur;
	/* create a dummy row as the new row souce */
	row nex = EROW;
	/* allocate a buffer */
	char *s = malloc(len + 1);
	//if (s == NULL) termDie("malloc in rowAddRow s");
	/* copy the contents of the pos row after the cursor into the buffer */
	memcpy(s, &b->rw[pos].chars[cur], len);
	s[len] = '\0';
	/* update the dummy row */
	nex.chars = s;
	nex.size = strlen(s);
	
	/* MAKE THE SPLIT INTO TWO LINES */
	/* shrink the line at pos */
	char *p = realloc(b->rw[pos].chars, cur + 1);
	//if (p == NULL) termDie("realloc in rowAddRow");
	b->rw[pos].chars = p;
	/* and terminate it with null like a good boi */
	b->rw[pos].chars[cur] = '\0';
	/* update info and render */
	b->rw[pos].size = cur;
	updateRender(&b->rw[pos]);

	/* copy the dummy to the new line and free */
	rowCpy(&b->rw[pos + 1], &nex);
	rowFree(&nex);

}

void rowFree (row *rw) // WIP
{
	/* Free both render and memory strings */
	free(rw->render);
	free(rw->chars);
	/* clear sizes */
	rw->size = 0;
	rw->r_size = 0;
	rw->utf = 0;
}

void rowCpy (row *to, row *from) // WIP
{
	/* Free the destination row (without destroying it) */
	rowFree(to);
	/* Allocate space for the new string */
	to->chars = (char*) malloc(strlen(from->chars) + 1);
	//if (to->chars == NULL) termDie("malloc in rowCpy");
	/* And update the size */
	to->size = from->size;
	/* Then copy the chars from the source row to the destination row */
	memcpy(to->chars, from->chars, to->size);
	to->chars[to->size] = '\0';
	/* Then update the render */
	updateRender(to);
}

void rowAppendString (row *rw, char *s, int len)
{
	/* reallocate the row to accomodate for the added string */
	char *temp = realloc(rw->chars, rw->size + len + 1);
	//if (temp == NULL) termDie("realloc in rowAppendString");
	rw->chars = temp;

	memcpy(&rw->chars[rw->size], s, len);
	rw->size += len;
	rw->chars[rw->size] = '\0';
	
	updateRender(rw);
}

void rowDeleteRow (buf *b, int pos)
{
	if (b->rownum == 1) return;
	if (pos >= b->rownum) return;
	if (pos < 0) return;

	for (; pos < b->rownum - 1; pos++) {
		rowCpy(&b->rw[pos], &b->rw[pos + 1]); // rowcpy already frees the row
	}
	b->rownum--;
	rowFree(&b->rw[b->rownum]);
	row *temp = realloc(b->rw, sizeof(row) * b->rownum);
	//if (temp == NULL) termDie("realloc in rowDeleteRow");
	b->rw = temp;
}

void updateRender (row *rw)
{
	/* count the special characters
	 * spaces, utf-8 continuation chars */
	static int tabs, i, off, cc, ut;
	for (i = 0, tabs = 0, cc = 0, ut = 0; i < rw->size; i++) {
		if (rw->chars[i] == '\t') tabs++;
		else if (isCont(rw->chars[i])) cc++;
		else if (isUtf(rw->chars[i])) ut++;
	}
	rw->render = NULL;
	free(rw->render);

	/* Render is long as size with the added tab spaces - 1
	 * (we already count for the \t as a char) */
	rw->render = malloc(rw->size + tabs * (TABSIZE - 1) + 1);
	//if (rw->render == NULL) termDie ("malloc in updateRender");

	/* put all the characters (substituing all special chars)
	 * into the render buffer */
	for (i = 0, off = 0; i < rw->size; i++) {
		if (rw->chars[i] == '\t') {
			for (int j = 0; j < TABSIZE; j++){
				//if (!j) rw->render[off++] = '|'; 
				//else rw->render[off++] = ' ';
				rw->render[off++] = ' ';
			}		
		} else {
			rw->render[off++] = rw->chars[i];
		}
	}
	rw->render[off] = '\0';
	rw->r_size = off - cc;
	rw->utf = cc + ut;
}